Genetic mechanisms underlying the pathogenesis of tropical calcific pancreatitis

Chronic pancreatitis is known to be a heterogeneous disease with varied etiologies.Tropical calcific pancreatitis(TCP) is a severe form of chronic pancreatitis unique to developing countries.With growing evidence of genetic factors contributing to the pathogenesis of TCP,this review is aimed at compiling the available information in this field.We also propose a two hit model to explain the sequence of events in the pathogenesis of TCP.

Comprehensive screening for reg1α gene rules out association with tropical calcific pancreatitis

AIM: To investigate the allelic and haplotypic association of reg1α gene with tropical calcific pancreatitis (TCP). Since TCP is known to have a variable genetic basis, we investigated the interaction between mutations in the susceptibility genes, SPINK1 and CTSB with reg1α polymorphisms. METHODS: We analyzed the polymorphisms in the reg1α gene by sequencing the gene including its promoter region in 195 TCP patients and 150 ethnically matched controls, compared their allele and haplotype frequencies, and their association with the pathogenesis and pancreaticolithiasis in TCP and fibro-calculous pancreatic diabetes. RESULTS: We found 8 reported and 2 novel polymo-rphisms including an insertion-deletion polymorphism in the promoter region of reg1α. None of the 5' UTR variants altered any known transcription factor binding sites, neither did any show a statistically significant association with TCP. No association with any reg1α variants was observed on dichotomization of patients based on their N34S SPINK1 or L26V CTSB status. CONCLUSION: Polymorphisms in reg1α gene, including the regulatory variants singly or in combination with the known mutations in SPINK1 and/or CTSB genes, are not associated with tropical calcific pancreatitis.

Genetic and phenotypic heterogeneity in tropical calcific pancreatitis

Tropical calcific pancreatitis(TCP)is a form of chronic non-alcoholic pancreatitis initially reported in the developing parts of the tropical world.The clinical phenotype of TCP has undergone marked changes since its first description in 1968.The disease is now seen in relatively older people with less severe symptoms.In addition,there are varying reports on the proportion of cases presenting with imaging abnormalities like calcification,ductal dilation,and glandular atrophy.Significant progress has also been made in understanding the etiopathology of TCP.The role of malnutrition and cassava toxicity in its pathogenesis is disproven and few studies have focused on the role of micronutrient deficiency and oxidative stress in the etiopathogenesis of TCP.Emerging evidence support an important role for genetic risk factors in TCP.Several studies have shown that,rather than mutations in trypsinogens,variants in serine protease inhibitor kazal type 1,cathepsin B,chymotrypsin C,cystic fibrosis transmembrane regulator,and carboxypeptidase A1,predict risk of TCP.These studies also provided evidence of mutational heterogeneity between TCP and chronic pancreatitis in Western populations.The current review summarizes recent advances that have implications in the understanding of the pathophysiology and thus,heterogeneity in genotype-phenotype correlations in TCP.